Partitioning ecological sites according to environmental factors (Case study: Taleghan rangelands)

To separate main ecological sites based on environmental factors 16 different soil properties (13 parameters) and topographic variables (3 variables) were investigated in Taleghan rangelands, Alborz Mountains. Sampling was done in 5 land units extracted from integration of geology, slope and elevation maps. Vegetation was studied using a random-systematic method along a100 meters transect in 5 meters length sampling unit that were located 20 meters from each other. Soil samples were taken from 0-30 cm depth at starting and ending points of each transect. To investigate similarity and difference between ecological sites, cluster analysis was done based on Euclidian distance and Wards method. ANOVA analysis followed by Duncan test was used to compare the environmental factors. Principle Component Analysis was used to determine the most important environmental factors partitioning ecological sites. Results of cluster analysis, showed 5 different plant groups in 57% dissimilarity. ANOVA results showed significant difference in soil organic carbon, nitrogen, lime, pH, potassium contents and soil depth between ecological sites. Principal component analysis also showed that soil nitrogen, potassium, organic carbon, calcium and clay contents as well as slope percentage are the most important factors separating different ecological sites.